The Ross River Dam is a rock and earthfill-filled embankment dam across the Ross River, located between Kelso and Mount Stuart in the City of Townsville in northern Queensland, Australia. Built initially for flood control, Lake Ross, the impoundment created by the dam, serves as one of the major potable water supplies for the region. The dam reached 250% capacity in February 2019 as a result of mass rainfall and flooding in the area.

Location and features

The dam was constructed by Leighton Contractors in 1971 for the purposes of flood mitigation and water storage. The dam was an attempt to address Townsville's dual water concerns--abundance and scarcity--and added to the city's long history of attempting to tame the natural environment. In the 1980s, the second stage of the dam necessitated a deviation of the Flinders Highway and Mount Isa railway line (which previously ran straight north-south) to be further east. This was completed by 1986 and resulted in the closure of Toonpan and Barringha railway stations on the removed route; they were not re-established on new route. Following a 2007 upgrade of facilities, the dam has a capacity of 250000 ML and an earth rock embankment 8.67 km in length and 34.4 m high. The reservoir has a catchment area of 750 km2 with a controlled gated spillway. The reservoir has a current capacity of 233187 ML of water; and can hold up to 803565 ML of water in flood mitigation. When the dam gates open, water spills over into the Ross River. Visitors may view the dam from a viewing platform at Ross Park. The Ross Dam Pump Station supplies up to 232 ML of water to the Douglas Water Treatment Plant, where the water undergoes aeration, sedimentation, rapid sand filtration and chlorination treatment before being pumped to the reservoir where the water is distributed to Townsville. At the base of the dam and on the banks of the Ross River is Ross Park, part of Riverway, with facilities for picnics or barbecues, as well as public toilets at this location.

Upgrade of the dam wall

The spillway gates have increased the dam's capacity by around nine percent, which is about 21000 ML or four months extra supply of water. Three spillway gates span the 40 m wide spillway. The upgrade was going to take until mid-2008 to complete unless rainfall delays construction, however it was completed ahead of time in late 2007. The cost was around A$115 million. The dam's storage was temporarily reduced with the lowering of the spillway to make way for the new floodgates that have now been fitted. Water is supplied to surrounding areas by releasing water from the Burdekin Dam spillway into the Burdekin and Haughton Rivers. Weirs control the volume of water entering each river. The Haughton pumping station supplies water via a low pressure pipeline to Ross River Dam. The pipeline was built in 1988 by the Townsville Council. During the first decade the PVC sections of the pipeline repeatedly ruptured.